Epidemiological characteristics of seasonal influenza under implementation of zero-COVID-19 strategy in China.

OBJECTIVE: Respiratory viral diseases have posed a persistent threat to public health due to their high transmissibility. Influenza virus and SARS-Cov-2 are both respiratory viruses that have caused global pandemics. A zero-COVID-19 strategy is a public health policy imposed to stop community transmission of COVID-19 as soon as it is detected. In this study, we aim to examine the epidemiological characteristics of seasonal influenza in the past five years before and after the emergence of COVID-19 in China and observe the possible impact of the strategy on influenza. METHODS: Data from two data sources were retrospectively analyzed. A comparison on influenza incidence rate between Hubei and Zhejiang provinces was conducted based on data from the Chinese Center for Disease Control and Prevention (CDC). Then a descriptive and comparative analysis on seasonal influenza based on data from Zhongnan Hospital of Wuhan University and Hangzhou Ninth People`s Hospital before and after the outbreak of SARS-CoV-2 was conducted. RESULTS: From 2010-2017, both provinces experienced relatively low influenza activity until the 1st week of 2018, when they reached peak incidence rates of 78.16/100000PY, 34.05/100000PY respectively. Since then, influenza showed an obvious seasonality in Hubei and Zhejiang until the onset of COVID-19. During 2020 and 2021, there was a dramatic decline in influenza activity compared to 2018 and 2019. However, influenza activity seemed to rebound at the beginning of 2022 and surged in summer, with positive rates of 20.52% and 31.53% in Zhongnan Hospital of Wuhan University and Hangzhou Ninth People`s Hospital respectively as of the time writing this article. CONCLUSIONS: Our results reinforce the hypothesis that zero-COVID-19 strategy may impact the epidemiological pattern of influenza. Under the complex pandemic situation, implementation of NPIs could be a beneficial strategy containing not only COVID-19 but also influenza.

Studying pulmonary fibrosis due to microbial infection via automated microscopic image analysis.

Introduction: Pulmonary fibrosis is a consequential complication of microbial infections, which has notably been observed in SARS-CoV-2 infections in recent times. Macrophage polarization, specifically the M2-type, is a significant mechanism that induces pulmonary fibrosis, and its role in the development of Post- COVID-19 Pulmonary Fibrosis is worth investigating. While pathological examination is the gold standard for studying pulmonary fibrosis, manual review is subject to limitations. In light of this, we have constructed a novel method that utilizes artificial intelligence techniques to analyze fibro-pathological images. This method involves image registration, cropping, fibrosis degree classification, cell counting and calibration, and it has been utilized to analyze microscopic images of COVID-19 lung tissue. Methods: Our approach combines the Transformer network with ResNet for fibrosis degree classification, leading to a significant improvement over the use of ResNet or Transformer individually. Furthermore, we employ semi-supervised learning which utilize both labeled and unlabeled data to enhance the ability of the classification network in analyzing complex samples. To facilitate cell counting, we applied the Trimap method to localize target cells. To further improve the accuracy of the counting results, we utilized an effective area calibration method that better reflects the positive density of target cells. Results: The image analysis method developed in this paper allows for standardization, precision, and staging of pulmonary fibrosis. Analysis of microscopic images of COVID-19 lung tissue revealed a significant number of macrophage aggregates, among which the number of M2-type macrophages was proportional to the degree of fibrosis. Discussion: The image analysis method provids a more standardized approach and more accurate data for correlation studies on the degree of pulmonary fibrosis. This advancement can assist in the treatment and prevention of pulmonary fibrosis. And M2-type macrophage polarization is a critical mechanism that affects pulmonary fibrosis, and its specific molecular mechanism warrants further exploration.

Home quarantine or centralized quarantine? A mathematical modelling study on the COVID-19 epidemic in Guangzhou in 2021.

Several outbreaks of COVID-19 caused by imported cases have occurred in China following the successful control of the outbreak in early 2020. In order to avoid recurrences of such local outbreaks, it is important to devise an efficient control and prevention strategy. In this paper, we developed a stochastic discrete model of the COVID-19 epidemic in Guangzhou in 2021 to compare the effectiveness of centralized quarantine and compulsory home quarantine measures. The model was calibrated by using the daily reported cases and newly centralized quarantined cases. The estimated results showed that the home quarantine measure increased the accuracy of contact tracing. The estimated basic reproduction number was lower than that in 2020, even with a much more transmissible variant, demonstrating the effectiveness of the vaccines and normalized control interventions. Sensitivity analysis indicated that a sufficiently implemented contact tracing and centralized quarantine strategy in the initial stage would contain the epidemic faster with less infections even with a weakly implemented compulsory home quarantine measure. However, if the accuracy of the contact tracing was insufficient, then early implementation of the compulsory home quarantine with strict contact tracing, screening and testing interventions on the key individuals would shorten the epidemic duration and reduce the total number of infected cases. Particularly, 94 infections would have been avoided if the home quarantine measure had been implemented 3 days earlier and an extra 190 infections would have arisen if the home quarantine measure was implemented 3 days later. The study suggested that more attention should be paid to the precise control strategy during the initial stage of the epidemic, otherwise the key group-based control measure should be implemented strictly.

Multi-Dimensional Evaluation Framework for the Sustainable Development of Forest Health Bases and Site Selection for Application in China

In the context of global aging, people’s awareness of health is deepening, and the rapid economic development has drawn widespread attention to the health tourism industry. As a way of experiencing health, forest health tourism is becoming increasingly favored, and the site selection and construction of forest health bases (FHBs) have also developed accordingly. To ensure sustainability in the process of the site selection and construction of FHBs, the suitability of regional development and the relative coordination of the market, environment, and resource levels should be considered. Although there have been numerous studies on sustainable forestry management, a comprehensive sustainability assessment framework based on development suitability and coordination in three dimensions is needed to guide the site selection and the construction of FHBs. The following tasks were carried out in this study: (1) based on market sustainability goals, environmental optimization goals, and ecological resource sustainability goals, a comprehensive sustainability evaluation framework for development suitability indicators and coordination indicators in three dimensions was established;(2) via the use of this framework, the construction potential of FHBs in 41,636 towns in China was evaluated;the evaluation results show that the towns in Anhui, Jiangxi, Guangdong, Guangxi, Fujian, Zhejiang, Hunan, Hubei, Guizhou, and other provinces of China generally have superior conditions for the development of FHBs;(3) a multi-dimensional comprehensive analysis of FHB site selection sustainability based on development suitability and coordination was carried out for four batches of approved pilots. The comprehensive analysis results demonstrate the worsening evaluation results of the four batches. The proposed framework can provide a reference for FHB development policies for countries worldwide.